Make /cfinditem much more powerful when the player is opped

src/main/java/net/earthcomputer/clientcommands/ClientcommandsDataQueryHandler.java

@@ -0,0 +1,65 @@
+package net.earthcomputer.clientcommands;
+
+import net.minecraft.client.network.ClientPlayNetworkHandler;
+import net.minecraft.nbt.NbtCompound;
+import net.minecraft.network.packet.c2s.play.QueryBlockNbtC2SPacket;
+import net.minecraft.network.packet.c2s.play.QueryEntityNbtC2SPacket;
+import net.minecraft.util.math.BlockPos;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.function.Consumer;
+
+public class ClientcommandsDataQueryHandler {
+    private final ClientPlayNetworkHandler networkHandler;
+    private final List<CallbackEntry> callbacks = new ArrayList<>();
+
+    public ClientcommandsDataQueryHandler(ClientPlayNetworkHandler networkHandler) {
+        this.networkHandler = networkHandler;
+    }
+
+    public static ClientcommandsDataQueryHandler get(ClientPlayNetworkHandler networkHandler) {
+        return ((IClientPlayNetworkHandler) networkHandler).clientcommands_getCCDataQueryHandler();
+    }
+
+    public boolean handleQueryResponse(int transactionId, @Nullable NbtCompound nbt) {
+        Iterator<CallbackEntry> callbacks = this.callbacks.iterator();
+        while (callbacks.hasNext()) {
+            CallbackEntry callback = callbacks.next();
+            if (callback.transactionId - transactionId > 0) {
+                break;
+            }
+            callbacks.remove();
+            if (callback.transactionId == transactionId) {
+                callback.callback.accept(nbt);
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private int nextQuery(Consumer<@Nullable NbtCompound> callback) {
+        int transactionId = ++networkHandler.getDataQueryHandler().expectedTransactionId;
+        callbacks.add(new CallbackEntry(transactionId, callback));
+        return transactionId;
+    }
+
+    public void queryEntityNbt(int entityNetworkId, Consumer<@Nullable NbtCompound> callback) {
+        int transactionId = nextQuery(callback);
+        networkHandler.sendPacket(new QueryEntityNbtC2SPacket(transactionId, entityNetworkId));
+    }
+
+    public void queryBlockNbt(BlockPos pos, Consumer<@Nullable NbtCompound> callback) {
+        int transactionId = nextQuery(callback);
+        networkHandler.sendPacket(new QueryBlockNbtC2SPacket(transactionId, pos));
+    }
+
+    private record CallbackEntry(int transactionId, Consumer<@Nullable NbtCompound> callback) {
+    }
+
+    public interface IClientPlayNetworkHandler {
+        ClientcommandsDataQueryHandler clientcommands_getCCDataQueryHandler();
+    }
+}